kc3-lang/gnulib/doc/posix-headers/stdnoreturn.texi

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• Hash : daba2833
  Author :
  Date : 2017-08-17T01:59:11
  

  stdnoreturn: Fix test compilation failure on Cygwin.
  
  * m4/stdnoreturn.m4 (gl_STDNORETURN_H): On Cygwin, use gnulib's
  <stdnoreturn.h> replacement.
  * lib/stdnoreturn.in.h (noreturn): Treat Cygwin like MSVC.
  * doc/posix-headers/stdnoreturn.texi: Mention the Cygwin problem.
  

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• doc/posix-headers/stdnoreturn.texi

• @node stdnoreturn.h
  @section @file{stdnoreturn.h}
  
  POSIX specification:@* Not in POSIX yet, but we expect it will be.
  ISO C11 (latest free draft
  @url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf})
  sections 7.23.
  
  Gnulib module: stdnoreturn
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  This header file is missing on most circa-2012 platforms.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  @code{<stdnoreturn.h>} should be #included before @samp{_Noreturn} is used.
  @item
  You cannot assume that @code{_Noreturn} is a reserved word;
  it might be a macro.
  @item
  When the macro @code{lint} is defined, standard headers define
  @code{_Noreturn} (and therefore @code{noreturn}) to be a macro that
  expands to the empty token sequence on some platforms:
  Cygwin 2.5.1, FreeBSD 10.3.
  @item
  On Cygwin 1.7.30 and MSVC 14, @code{noreturn} expands to the empty token
  sequence, to avoid problems with standard headers that use @code{noreturn}
  in combination with @code{__attribute__} or @code{__declspec}.  Although
  the resulting code operates correctly, the compiler is not informed whether
  @code{noreturn} functions do not return, so it may generate incorrect
  warnings at compile-time, or code that is slightly less optimized.  This
  problem does not occur with @code{_Noreturn}.
  @item
  Circa 2012 bleeding-edge GCC with @code{-Werror=old-style-declaration}
  requires @code{_Noreturn} or @code{noreturn} before the returned type
  in a declaration, and therefore rejects valid but unusually-worded
  declarations such as @code{void _Noreturn foo (void);}.
  @end itemize
  

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